﻿using System;
using System.Collections.Generic;
using System.Text;

namespace 杂项
{
    class Fanxing
    {
        public Fanxing()
        {
            List<A> BS = new List<A>();
            BS.Add(new B());
            SS(BS);
        }

        List<A> SS(List<A> d)
        {
            return d;
        }

        public class A
        {
        }
        public class B : A
        {
        }

        interface it
        { }
    }
}
